Detached garage slab - control joints 1

[Woody1515]

Hello!

Let’s say you are pouring a 24’X24’ slab on grade for a detached garage. You have the typical edge thickening under the exterior walls, vapour barrier and compacted gravel under the slab, etc. Is it still common practice to create control joints in the slab? If so, what would the layout of the joints looks like? Something like an X that intersects the slab into 4 12’X12’ sections? I cannot ever remember seeing control joints in a detached garage slab...

Thanks in advance!

 

[jayrod12]

Most people just accept the likelihood of random cracking

 

[Ron]

Control joints at 12' each way. Sawcut the same day as placement. Cut depth should be 20-25 percent of thickness.....otherwise you will get unsightly "random" cracks

 

[SoilRocks]

ALWAYS put in control joints. The very general rule of thumb is to keep the sections square as possible, and to space the control joints at a maximum of about 24 times the slab thickness. So, if a slab is 5 inches thick, put the control joints at 10 feet (Reinforcement helps extend that). For a very limited space, 12-foot squares should do it. I agree with Ron on paying proper attention to the control joints.